Research: Breast Cancer Center of Excellence
The Breast Cancer Center of Excellence of the Comprehensive Cancer Center concentrates its research efforts on four specific themes:
Biology of Breast Carcinogenesis and Malignant Progression
With regard to the theme of the biology of breast carcinogenesis and malignant progression:
- Guangchou Sui, PhD, provided strong in vitro evidence that the transacting transcriptional activator/repressor YinYang1 (YY1) is a breast tumor promoting protein. Dr. Sui found that YY1 regulates the aberrant epigenetics of breast cancer. He applied for RO1 funding to support this investigation.
- In a similar vein, Kazushi Inoue, PhD, observed that the transcriptional activator Dmp1 serves as a breast tumor suppressor. Dmp1 is itself activated via the Her2-neu-PI3 kinase pathway, and, in turn, stimulates Arf and p21 transcription. MMTV-neu-driven tumorigenesis was significantly accelerated in both Dmp1+/- and Dmp1-/- mice and ca. 50 percent of human breast cancer samples demonstrate loss of heterozygosity at the Dmp1 locus. This work is supported by an American Cancer Society Scholar award to Dr. Inoue and a Department of Defense Postdoctoral Training Award to Dr. Inoue’s postdoctoral student, Dr. P. Taneja.
- Darren Seals, PhD, is studying the mechanisms whereby macrophages recognize and infiltrate breast cancers. The major focus of his work is on mechanisms of macrophage motility and the implications of macrophage infiltration on breast cancer progression.
- Iris Edwards, PhD, is interested in potential anti-breast cancer mechanism of omega-3 polyunsaturated fatty acids. She is investigating the hypothesis that the proteoglycan, syndecan-1, is an important regulator of tumor growth and metastasis and that syndecan-1 metabolism is regulated by omega-3 PUFA. Syndecan-1 is a transmembrane heparan sulfate proteoglycan, expressed on mammary epithelial cells that are known to regulate biological processes including cytoskeletal organization, growth factor signaling, and cell-cell adhesion. Dr. Edwards has shown that syndecan-1 expression is markedly lower in human breast cancer cell lines compared to their non-tumorigenic counterparts. However, syndecan-1 mRNA and protein is increased by treating tumor cells with omega -3 PUFA, as well as in mammary tissues of Fat-1 mice that express the c elegans transgene for converting omega-6 to omega-3 PUFA. Dr. Edwards identified a novel pathway that provides a mechanism for the anti-tumor properties of omega-3 PUFA as follows: the omega-3 PUFA, docosahexaenoic acid (DHA) activates the nuclear transcription factor PPARg that results in transcriptional up-regulation of the sdc-1 target gene, and the syndecan-1 protein induces cell apoptosis. This work is supported by RO1 funding from the NCI.
- Linda Metheny-Barlow, PhD, has been investigating the mechanisms by which breast tumor cells alter mural cell phenotype to help maintain tumor vessels in an immature and angiogenic state. She observed that the presence and function of connexin Cx43 is required for mural cell inhibition of endothelial proliferation, and that breast tumors downregulate Cx43 protein and gap junction activity of mural cells. Her ongoing efforts seek to elucidate the mechanisms by which breast tumors regulate Cx43 and ways to override it to restore vessel stabilization, and to validate her finding in vivo using xenograft models and human breast tumor specimens. This work is RO1 funded.
Dr. Metheny-Barlow has also been developing and characterizing syngeneic rodent models of breast cancer metastasis to study mechanisms of metastasis as well as for the testing of potential therapeutics. She has passaged 4T1 cells through the brain of syngeneic Balb/c mice five times to result in cell lines with increasing specificity for growth in the brain. Using microarray analysis, Dr. Metheny-Barlow has identified a number of genes with altered regulation in brain-selected lines compared to parental cells and is currently evaluating them for their potential contributions to the aggressiveness and selectivity of these cells for the brain. In collaboration with other faculty, she will use another rodent model of breast to brain metastasis (MATBIII cells in Fischer344 rats) to evaluate compounds for their ability to prevent radiation-induced cognitive defects in a tumor-bearing model.
Finally, Dr. Metheny-Barlow is assessing the potential of a dietary carotenoid, Astaxanthin, as a cancer therapeutic. We are currently assessing the ability of this compound to sensitize breast cancer cells to conventional chemo- and radiation therapies, as well as examining the anti-invasive and anti-metastatic properties of this agent, which may indicate its utility to treat or prevent the metastatic spread of cancer.
- J. Mark Cline, DVM, PhD is performing groundbreaking studies of the effects of hormones and dietary soy on breast carcinogenesis, utilizing the macaque monkey model. Dr. Cline and collaborators documented breast and cervical cancer occurring naturally in monkeys at similar incidence to human beings, with similar hormonal risk factors in the case of the breast, and similar viral etiology in the cervix. They did a number of prospective trials in monkeys to evaluate effects on hormone-responsive tissues; treatments evaluated for their effects on cancer risk include estrogens, soy isoflavonoid “phytoestrogens”, progestogens, androgens, and selective estrogen response modifiers (SERMs). Endpoints evaluated include gene expression profiles, histology, histomorphometry, and specific outcomes such as cell proliferation (Ki-67), expression of sex steroid receptors (ER alpha and beta, PR A and B, AR), and the expression and activity of estrogen metabolizing enzymes in breast. Dr. Cline's group has also performed translational studies in human subjects, including retrospective study of the effects of dietary soy on breast cancers in women through collaboration with the Cancer Research Center of Hawaii.
Their most interesting experimental findings in the last five years include the following:
- Soy isoflavones inhibit estrogen-metabolizing enzymes in vitro (collaboration with Dr. Alan Townsend) (Scott et al., JSBMB 2008).
- Estradiol induces four-fold more proliferation in the breast of primates than do conjugated equine estrogens, when given at clinically relevant doses (Wood et al., 2008).
- Dietary soy consumption does not appear to increase expression of proliferation markers in breast cancers of women (Maskarinec et al., 2009).
- Medroxyprogesterone acetate produces a distinctly different gene expression pattern in the breast, compared to progesterone (Wood et al, BCRT 2009).
- Testosterone does not antagonize the effect of estrogen plus progestogen treatment on the mammary gland (Wood et al., Menopause 2009)
- Endometrial gene expression profiles of tamoxifen overwhelm the patterns produce by estradiol when the two are co-administered, indicating potential for less uterotrophic selective estrogen receptor modulators (SERMS) to serve as a replacement for progestins without increasing breast cancer risk (Wood el al., 2010).
Dr. Cline’s work is supported by RO1 funding from the National Center for Complementary and Alternative Medicine (NCCAM).
Analysis of Large Data Sets (“Omics”) for Identification of Breast Cancer Predictive Markers
- Genomics expert Lance Miller, PhD, in collaboration with iron metabolism experts Frank M. Torti, MD, MPH, and Dr. Suzy Torti, analyzed breast cancer patient gene expression data derived from microarray assays. They made the novel high-impact discovery that expression of iron efflux proteins ferroportin and hepcidin are important modulators of the risk of recurrence of primary breast cancer. This observation, which was vetted in an animal model, and reported in Science Translational Medicine, links intracellular iron availability to breast cancer aggressiveness and proliferative potential.
- Lipid biochemists Joseph O’Flaherty, MD, and Dr. Iris Edwards, in collaboration with Steven A. Akman, MD, are assessing fatty acid and eicosanoid profiles in patient-derived benign and malignant breast tissue. Although the fatty acid profiles of benign vs. malignant breast tissue are quite similar, the eicosanoid profiles are not. Omega-6 fatty acid metabolites prostaglandin (PG)E2, 5-hydroxy-eicosatetraenoate (HETE), 12-HETE, 15-HETE, and 13- hydroxy-octadecadienoic acid (HODE) are all markedly elevated in malignant breast tissue in comparison to benign tissue. This observation has lead to formulation of an interventional clinical trial of omega-3 fatty acid supplementation with monitoring of tissue eicosanoids in newly diagnosed breast cancer patients, for which funding has been applied. The initial studies were funded by pilot funds provided by the Cancer Center and the Golfers Against Cancer.
- Dr. Steve Akman, in collaboration with nutritional epidemiologist Dr. Mara Vitolins, and Dr. Vladimir Shulaev and Reinhard Laubenbacher, PhD, of the Virginia Bioinformatics Institute, are conducting a metabolomic analysis of plasma derived from newly diagnosed breast cancer patients vs. normal healthy female volunteers in a search for metabolic plasma biomarkers of early breast cancer. Plasma metabolomes have been analyzed by GC- and LC-MS and unsupervised and supervised statistical algorithms have been used to segregate samples and identify markers. To date, the analysis has identified several MS peaks as potential breast cancer discriminators. The study has recently proceeded to a validation phase. This project has been supported by a grant from the Translational Science Institute of Wake Forest University.
Quality of Life and Survivorship Issues
Dr. Suzanne Danhauer is conducting a study entitled “Yoga during Breast Cancer Treatment: Establishing Community-Based Partnerships” which involves translating her yoga research from an academic cancer center to community partners in the CCOP Research Base. Her primary mentor on this award is Dr. Nancy Avis.
Secondary mentors are Dr. Michelle Naughton (Cancer Control) and Julia Lawrence, DO, (Clinical Research Program). This study was approved by the National Cancer Institute and opened in early 2010. At present, she is developing a companion concept for a study of the same cancer-specific yoga intervention that will target women undergoing radiation therapy for breast cancer. This work is currently supported by a Translational Scholar Award from the Translational Science Institute of Wake Forest University.
Women’s Health Initiative (WHI)
- Dr. Michelle Naughton headed a Behavioral Center of Excellence in Breast Cancer at Wake Forest, one of only four nationwide funded by the Department of Defense. The Center focused on quality of life and functional status of breast cancer survivors. Dr. Naughton has particularly focused on menstrual cycle maintenance in premenopausal breast cancer survivors.
- Dr. Shannon Mihalko, in collaboration with Dr. Roger Anderson, is studying the impact of regular supervised exercise on quality of life and outcomes in breast cancer survivors. The RESTORE study randomized breast cancer survivors to either a supervised regular exercise program vs. an educational program, with outcomes of quality of life indices and the incidence and severity of arm lymphedema.
- Dr. Mara Vitolins, in collaboration with Dr. Mihalko, is following up the RESTORE study with a second-generation study of the effect of supervised aerobic physical exercise on measures of physical and aerobic function as well as measures of psychosocial well being.
- Kathryn Weaver, PhD, MPH, recently joined the faculty of the Department of Public Health Sciences after completion of a Cancer Prevention Fellowship at the NCI. Dr. Weaver has moved rapidly to initiate studies of health behavior among breast cancer survivors and their family caregivers, patterns of follow-up care among breast cancer survivors, and breast cancer health disparities.
Novel Imaging and Therapeutics
- Greg Hundley, MD, pioneered the use of magnetic resonance imaging (MRI) to detect chemotherapy-induced cardiovascular injury in breast cancer patients. Among the studies recently conducted by Dr. Hundley are:
- A study of optimized cardiac magnetic resonance (CMR) imaging of chemotherapy-induced cardiotoxicity. This study recruited 99 cancer patients to evaluate the presence of imaging markers of subclinical CV disease in individuals treated with cardiotoxic chemotherapy with collection of biochemical markers of cardiac structure and function to determine relationship to CMR findings. The study was supported by NCI grant support
- A study of early detection of chemotherapy-induced cardiotoxicity in women with breast cancer. This study recruited 27 breast cancer patients to determine the association between adjuvant chemotherapy that included the anti-HER2 antibody trastuzumab and imaging markers of subclinical cardiovascular disease. The Susan G. Komen Foundation supported this study.
- A study of longitudinal variance measurements of new dynamic T1 cardiovascular magnetic resonance method in healthy subjects. This study recruited 16 healthy subjects to investigate the longitudinal variability of noncontrast MRI methods to detect cardiovascular injury. This study was supported by pilot funds provided by the WFUCCC.
- Dr. Hundley’s most recent study is a pilot to test breast cancer patient tolerance for statin therapy. Its goal is to determine the feasibility of administrating Rosuvastatin while undergoing chemotherapy. Statin therapy has been shown to prevent cardiovascular events in other populations at risk for cardiac disease. This study is supported by the Kulynych Interdisciplinary Cancer Research Fund.
Dr Fred Salsbury, PhD used computational modeling in combination with experiments performed by collaborators, to demonstrate that the DNA mismatch repair protein MSH2 binds platinated DNA differently then mismatched DNA, which results in the initiation of poptotic signaling.
Dr. Salsbury used molecular dynamics and molecular docking studied to identify candidate small molecules that mimic platinated DNA with regard to binding MSH2. NIH funding has been received to study this binding and to develop more candidate small molecules in collaboration with colleagues at Wake Forest University and Georgia Southern Uninversity and DOD funding has been received to develop these potential new anti-breast cancer agents in preclinical breast cancer models in vivo.
- Dr. Julia Lawrence is conducting a Phase I clinical trial assessing the feasibility of adding the vitamin D analog paracalcitol to cytotoxic chemotherapy with a taxane or epothilone in patients with evaluable metastatic breast cancer.
- Dr. Lawrence is also conducting a clinical trial of the fully human monoclonal anti-HER1 antibody panitumumab in combination with carboplatin plus paclitaxel in patients with triple negative metastatic breast cancer. Amgen Corp. supports this Wake Forest investigator initiated trial.
- John Stewart, MD, is the Wake Forest PI of a multicenter trial of a HER2 peptide vaccine for the prevention of recurrence in node positive or high-risk node negative patients.